A group of MPs wants the government to push the United Nations to impose sanctions against Sudan for failing to curb atrocities in the Darfur region.
Fleeing civilians have sought protection in camps
The Commons International Development Committee accuses Sudan authorities of blocking international peace-keepers.
The MPs say militias responsible for the violence are still attacking civilians, including refugee camps.
More than two million people have been forced from their homes and at least 180,000 have died in the conflict.
The struggle between the Khartoum government and Darfur rebels in the western Sudanese state began in early 2003.
MPs say peacekeeping African Union (AU) forces, which are monitoring an uneasy ceasefire, are overstretched.
Malcolm Bruce, the Liberal Democrat MP who chairs the committee, said inaction could lead to "another Rwanda".
About 800,000 Tutsis and moderate Hutus were slaughtered by Hutu extremists in Rwanda in 1994, one of the century's worst massacres.
Mr Bruce told BBC Radio 4's Today programme that, if the militias "were to turn on those camps, there is nothing on the ground that could save those people.
"That is what is causing concern and alarm, that we have millions of people at risk and a very small - although effective - force there to protect them."
MPs say the 6,000 AU peacekeepers should be given a full UN mandate and massive additional resources.
In the report published on Thursday, entitled Darfur: The Killing Continues, the committee says the main priority is to end bloodshed in the region.
In addition, the report is scathing about the Sudanese authorities, saying the government has failed to reign in militias.
On Wednesday, Tony Blair promised to do more to help refugees in the region and said strengthening peacekeeping forces should be a priority.
UN Secretary General Kofi Annan has called for plans to deploy a new, Western-backed rapid reaction force with air support and sophisticated equipment.
He said rapes and murders were continuing in the region.
The UN's special representative in Sudan, Jan Pronk, told the Security Council last month that at least once a month groups of up to 1,000 militia on horseback kill and terrorise local people.
He said the current peace strategy had failed, and a bigger, stronger force should go to Darfur.
Sudan has accused Western nations, such as the US, of exaggerating the problems in Darfur for political reasons.